CN111694231B

CN111694231B - Toner and method for producing the same

Info

Publication number: CN111694231B
Application number: CN202010161648.2A
Authority: CN
Inventors: 天野翔太; 川口新太郎; 中山宪一
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2019-03-14
Filing date: 2020-03-10
Publication date: 2024-05-24
Anticipated expiration: 2040-03-10
Also published as: US11112714B2; CN111694231A; JP7224976B2; US20200292956A1; EP3709087A1; JP2020148928A

Abstract

The present invention relates to a toner. The toner includes: toner particles; and an external additive, wherein the external additive comprises spherical silica particles and hydrotalcite particles, the spherical silica particles have a number average particle diameter Da of 10nm to 40nm, the spherical silica particles have a circularity of 0.80 or more, and the toner satisfies the following formula (1): { Ga X (1-Ka%) }/{ Gb X (1-Kb%) } is greater than or equal to 0.050 (1) wherein Ga: content of spherical silica particles Gb: content of hydrotalcite particles Ka%: fixation ratio kb% of spherical silica particles on toner particle surface: fixation ratio of hydrotalcite particles on the surface of toner particles.

Description

Toner and method for producing the same

Technical Field

The present invention relates to a toner suitable for an image forming method such as an electrophotographic method.

Background

In recent years, in addition to miniaturization, high speed, and long life, copiers and printers are required to produce stable images in any environment without deteriorating image quality.

In order to meet such a demand, a toner using hydrotalcite particles having a high charge imparting ability even at high temperature and high humidity as an external additive has been proposed.

Japanese patent application laid-open No. 2000-35692 proposes that by externally adding hydrotalcite particles to a toner, a toner having excellent properties even at high temperature and high humidity can be obtained. This shows that when hydrotalcite particles are present on the surface of the toner particles, the hydrotalcite particles can increase the charge by acting as micro carriers (microcarrier) when the charge decays.

Although the above toner exhibits excellent charging characteristics, there are problems associated with high durability. In particular, when the toner in the developing machine is strongly rubbed during high-speed printing, hydrotalcite particles may be detached from the toner particles, resulting in contamination of components in the developing machine.

Japanese patent application laid-open No. 2018-40967 discloses a method of suppressing detachment of hydrotalcite particles by combining spherical particles and hydrotalcite particles and electrostatically interacting these materials.

Disclosure of Invention

However, when the present inventors intensively studied further speed-up and life-increasing of the developing device, it is understood that the hydrotalcite particles and other external additives easily form aggregates (AGGREGATED LUMP) in the latter half of durable use when using the technique disclosed in the aforementioned patent document. It can also be appreciated that developing streaks are generated starting from the aggregate. It is further understood that the charge imparting function of the hydrotalcite particles is lost due to the generation of agglomerates.

The invention provides a toner which can maintain high image quality even if used for a long time regardless of environment.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following toners.

A toner, comprising:

toner particles; and

The additive agent is added to the mixture of the external additive agent and the water,

Wherein the external additive comprises spherical silica particles and hydrotalcite particles,

The spherical silica particles have a number average particle diameter Da of 10nm to 40nm,

The sphericity of the spherical silica particles is 0.80 or more, and

The toner satisfies the following formula (1):

{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050 (1)

wherein Ga: content of the spherical silica particles relative to 100 parts by mass of the toner particles

Gb: the hydrotalcite particles are contained in an amount of 100 parts by mass relative to the toner particles

Ka%: fixation ratio of the spherical silica particles on the surface of the toner particles (fixing ratio)

Kb%: fixation ratio of the hydrotalcite particles on the surface of the toner particles.

According to the present invention, a toner capable of maintaining high image quality even in long-term use regardless of the environment can be provided.

Further features of the invention will become apparent from the following description of exemplary embodiments.

Detailed Description

Unless otherwise indicated, in the present invention, a description of a numerical range such as "XX to YY" or "XX to YY" includes numerical values of the upper and lower limits of the numerical range.

The present invention will be described in detail below.

The present invention relates to a toner comprising:

toner particles; and

The sphericity of the spherical silica particles is 0.80 or more, and

The toner satisfies the following formula (1):

{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050 (1)

Ka%: fixation ratio of the spherical silica particles on the surface of the toner particles

The present inventors determined the following reasons why the effects of the present invention can be obtained by satisfying the above conditions.

In the case of the usual non-spherical silica particles, the contact area with the hydrotalcite particles is large and the formation of agglomerates is easy, but when the aforementioned specific spherical silica particles are used in a range where the relation of the fixation ratio satisfies the formula (1), the formation of agglomerates can be suppressed. As a result, in the latter half of durable use, the generation of developing streaks due to aggregated masses can be eliminated, and the function of hydrotalcite particles can be continuously exhibited.

The number average particle diameter (Da) of the spherical silica particles is 10nm to 40nm. When the number average particle diameter is in the above range, the silica particles enter the aggregated mass of the hydrotalcite particles, and thus the structure is more heterogeneous than the aggregated mass formed of only the hydrotalcite particles. As a result, even by the force applied in the developing machine, the aggregation is easily broken.

The number average particle diameter (Da) of the spherical silica particles is preferably 12nm to 38nm, more preferably 14nm to 36nm.

In addition, the sphericity of the spherical silica particles needs to be 0.80 or more. Within the above range, the contact area with hydrotalcite particles is smaller than in the case of non-spherical silica particles, and the deagglomeration of the agglomerate can be promoted.

The sphericity of the spherical silica particles is preferably 0.85 or more, and more preferably 0.90 or more. Meanwhile, the upper limit is not particularly limited, but is preferably 0.99 or less, more preferably 0.98 or less. The sphericity of the spherical silica particles can be controlled by the conditions during the production of the external additive. For example, the circularity can be controlled to the above range by the difference in surface tension between the raw material monomer and the reaction field.

Further, the toner of the present invention needs to satisfy the following formula (1). When the formula (1) is satisfied, a certain amount of spherical silica particles not fixed to the surfaces of the toner particles exist in the developing machine while moving between the toner particles. In this state, the spherical silica particles can intrude into the aggregated mass of the hydrotalcite particles, and will exhibit an effect of suppressing the generation of the aggregated mass (aggregation suppressing effect). As a result, hydrotalcite is less likely to form agglomerates, and its function as a micro carrier can be maintained.

When the value of formula (1) is less than 0.050, the amount of spherical silica particles that can move between toner particles is small, and there is no aggregation suppressing effect, thus generating aggregation and causing image defects of development streaks.

The value of formula (1) is preferably 6.000 or less. That is, the following formula (1') is preferably satisfied.

The value of formula (1) is preferably 0.500 or more. Meanwhile, the upper limit is more preferably 2.000 or less. Since the amount of spherical silica particles migrating from the toner is not excessively larger than the amount of hydrotalcite particles weakly fixed to the surface of the toner particles, the addition effect of the hydrotalcite particles can be easily obtained.

{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050 (1)

{6.00≥{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050}(1')

Ga: content of spherical silica particles relative to 100 parts by mass of toner particles

Gb: content of hydrotalcite particles relative to 100 parts by mass of toner particles

Ka%: fixation ratio of spherical silica particles on the surface of toner particles

Kb%: fixation ratio of hydrotalcite particles on the surface of toner particles

The content of the spherical silica particles is preferably 0.10 to 5.00 parts by mass, more preferably 0.5 to 1.5 parts by mass, with respect to 100 parts by mass of the toner particles.

When the content of the spherical silica particles is 0.10 parts by mass or more, the effect of suppressing aggregation of the spherical silica particles is easily exerted. Meanwhile, when the content of the spherical silica particles is 5.00 parts by mass or less, the spherical silica particles tend to be uniformly and firmly fixed on the surface of the toner particles, and functions as hydrotalcite particles exhibiting a micro carrier function are easily exerted.

The fixation rate Ka% of the spherical silica particles on the toner particle surface is preferably 60% to 95%, and more preferably 70% to 85%. When the fixation ratio is 60% or more, the function of the micro carrier of the hydrotalcite particles is easily exhibited, and when the fixation ratio is 95% or less, the effect of suppressing the formation of the aggregated mass is exhibited. The fixation ratio Ka% can be controlled by the number average particle diameter, the addition amount and the external addition strength.

The ratio Db/Da of the number average particle diameter Db of the hydrotalcite particles to the number average particle diameter Da of the spherical silica particles is preferably 7.5 or more, more preferably 8.0 or more. Meanwhile, the upper limit is not particularly limited, but is preferably 35.0 or less, more preferably 30.0 or less.

When Db/Da is 7.5 or more, the effect of the present invention can be obtained more easily. This is because the hydrotalcite particles are sufficiently large compared to the spherical silica particles, and even when a small amount of spherical silica particles adhere to the hydrotalcite particles, it is difficult to cause a decrease in the function of the hydrotalcite particles.

Hereinafter, the silica particles used in the present invention will be described.

The silica particles may be exemplified by wet silica manufactured from water glass, sol-gel silica particles manufactured by a sol-gel method, gel method silica particles, hydrocolloid silica particles, alcoholic silica particles, and fused silica particles obtained by a gas phase method, deflagration method silica particles, and the like. Sol-gel silica particles are preferred because of high circularity and sharp particle size distribution, and sol-gel silica particles that have been hydrophobized are particularly preferred.

Examples of the water repellent include unmodified silicone varnishes, various modified silicone varnishes, unmodified silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds and organotitanium compounds. These treating agents may be used alone or in combination.

The number average particle diameter Db of the hydrotalcite particles is preferably 0.10 μm to 1.00 μm, and more preferably 0.20 μm to 0.80 μm. When Db is 0.10 μm or more, the effect of maintaining electrification by hydrotalcite particles as a micro carrier is improved. Meanwhile, when Db is 1.00 μm or less, the hydrotalcite particles are less likely to be detached from the toner particles, and an agglomerate from the hydrotalcite as a starting point is less likely to be generated.

The hydrotalcite particles are preferably hydrophobized with a surface treatment agent in order to improve environmental stability. As the surface treatment agent, higher fatty acids, coupling agents, esters, and oils such as silicone oil can be used. Of these, higher fatty acids are preferably used, and specific examples thereof include stearic acid, oleic acid, and lauric acid.

The content of the hydrotalcite particles is preferably 0.05 to 1.00 parts by mass, and more preferably 0.10 to 0.80 parts by mass, with respect to 100 parts by mass of the toner particles.

When the amount is 0.05 parts by mass or more, the function of hydrotalcite particles is easily exhibited, and fogging can be suppressed from the early stage of durability. When the amount is 1.00 parts by mass or less, the hydrotalcite particles can be easily and uniformly fixed to the surface of the toner particles, and development streaks due to part contamination caused by the generation of aggregates can be suppressed.

The fixation rate Kb% of the hydrotalcite particles on the toner particle surface is preferably 15% to 70%, and more preferably 15% to 65%. When Kb% is 15% or more, generation of aggregation is easily suppressed, and suppression of contamination of components such as a developing blade is also effective. When Kb% is 70% or less, it is likely to function as a micro carrier. The fixation rate Kb% can be controlled by the number average particle diameter, the addition amount and the external addition strength.

The hydrotalcite particles are not particularly limited as long as the above characteristics are satisfied, but particles represented by the following structural formula may be used.

M²⁺ _yM³⁺ _x(OH)₂A^n- _(x/n)·mH₂O

(M ²⁺ represents a divalent metal ion, M ³⁺ represents a trivalent metal ion, A ^n- represents an n-valent anion, 0< x.ltoreq.0.5, x+y=1, and m.gtoreq.0.)

The divalent metal ion and the trivalent metal ion may be solid solutions including a plurality of different elements, or may include a trace amount of monovalent metal ion in addition to these metal ions.

Examples of metals that provide divalent metal ions include Mg, zn, ca, ba, ni, sr, cu and Fe. Examples of metals that provide trivalent metal ions include Al, B, ga, fe, co and In. Mg ²⁺ is preferable as a divalent metal ion, and Al ³⁺ is preferable as a trivalent metal ion.

N-valent anions can be exemplified by CO₃ ^2-、OH^-、Cl^-、I^-、F^-、Br^-、SO₄ ^2-、HCO₃ ^2-、CH₃COO^- and NO ^3-, and these anions can be present alone or in combination of a plurality thereof.

Hydrotalcite particles are represented by Mg ₆Al₂(OH)₁₆CO₃·4H₂ O, for example. The method for producing hydrotalcite particles is not particularly limited, and known methods may be used, and natural products or artificial products may be used.

In addition to the spherical silica particles and hydrotalcite particles described above, organic or inorganic fine particles generally known as external additives may be added to the toner. In this case, the total amount of the inorganic particles and the organic particles including hydrotalcite particles is preferably 0.5 parts by mass to 5.0 parts by mass with respect to 100 parts by mass of the toner particles. When the total amount of the fine particles is 0.5 parts by mass or more, the fluidity of the toner is good, and when the total amount of the fine particles is 5.0 parts by mass or less, contamination of the member by the toner and the external additive can be suppressed.

As the inorganic fine particles externally added to the toner particles, in addition to spherical silica particles and hydrotalcite particles, for example, inorganic particles selected from silica, alumina, titania or a composite oxide thereof may be used. Examples of the composite oxide include silica-alumina composite oxide, silica-titania composite oxide, strontium titanate particles, and the like.

These external additives are preferably used after hydrophobization of their surface. Examples of the hydrophobizing treatment include treatment with an organosilicon compound, silicone oil, long-chain fatty acid, and the like.

Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisilane, and the like. These may be used singly or as a mixture of two or more thereof.

Examples of the silicone oil include dimethyl silicone oil, methyl phenyl silicone oil, alpha-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

The toner may further include other additives, for example, a lubricant such as Teflon (registered trademark) powder, zinc stearate powder, polyvinylidene fluoride powder, an abrasive such as cerium oxide powder and silicon carbide powder, and a blocking preventing agent, and organic fine particles. These additives may also be used after surface hydrophobization.

Examples of the organic fine particles include homopolymers or copolymers of monomer components such as styrene, acrylic acid, methyl methacrylate, butyl acrylate and 2-ethylhexyl acrylate used in the toner binder resin obtained by, for example, emulsion polymerization or spray drying.

The method for producing the toner particles is not particularly limited, and known methods can be adopted. For example, a method of directly producing a toner in a hydrophilic medium, such as an emulsion aggregation method, a dissolution suspension method, or a suspension polymerization method, may be mentioned. Further, a pulverization method may be used, and the toner obtained by the pulverization method may be subjected to thermal spheroidization.

Among them, the effect of the present invention is easily obtained with a toner manufactured by an emulsion aggregation method. That is, the toner particles are preferably emulsion aggregation toner particles. The reason is that the coagulant used in the manufacturing process has polyvalent metal ions. The presence of the polyvalent metal ion in the binder resin allows the generated charge to be dispersed inside the toner, and can further stabilize the charging performance of the toner. The polyvalent metal ion is preferably at least one selected from the group consisting of aluminum ion, iron ion, magnesium ion and calcium ion.

Hereinafter, a method of manufacturing toner particles by emulsion aggregation will be exemplified and described in detail.

(Step of preparing a Dispersion)

The binder resin particle dispersion is prepared, for example, as follows. When the binder resin is a homopolymer or copolymer of an ethylene-based monomer (ethylene-based resin), the ethylene-based monomer is subjected to emulsion polymerization or seed polymerization in an ionic surfactant to prepare a dispersion in which ethylene-based resin particles are dispersed in the ionic surfactant.

When the binder resin is a resin other than the vinyl resin, such as a polyester resin, the resin is mixed with an aqueous medium in which an ionic surfactant or a polyelectrolyte is dissolved.

Thereafter, the solution is heated to the melting point or softening point of the resin to cause dissolution, and a dispersion device having a strong shearing force, such as a homogenizer, is used to prepare a dispersion in which the binder resin particles are dispersed in the ionic surfactant.

The means of dispersion is not particularly limited, and examples thereof include known dispersing devices such as a rotary shear type homogenizer, and ball mills, sand mills, and danomiles (dyno mill) having a medium.

In addition, a phase inversion emulsification method can be used as a method for preparing the dispersion liquid. In the phase inversion emulsification method, a binder resin is dissolved in an organic solvent, a neutralizing agent and a dispersion stabilizer are added as needed, an aqueous solvent is dropped under stirring to obtain emulsified particles, and then the organic solvent in the resin dispersion is removed to obtain an emulsion. At this time, the order of addition of the neutralizing agent and the dispersion stabilizer may be changed.

The number average particle diameter of the binder resin particles is usually 1 μm or less, preferably 0.01 μm to 1.00 μm. When the number average particle diameter is 1.00 μm or less, the finally obtained toner has a suitable particle diameter distribution, and generation of free particles can be suppressed. In addition, when the number average particle diameter is within the above range, uneven distribution among toner particles is reduced, dispersion in toner becomes good, and variation in performance and reliability is reduced.

In the emulsion aggregation method, a colorant particle dispersion may be used as needed. The colorant particle dispersion is obtained by dispersing at least colorant particles in a dispersant. The number average particle diameter of the colorant particles is preferably 0.5 μm or less, and more preferably 0.2 μm or less. When the number average particle diameter is 0.5 μm or less, irregular reflection of visible light can be prevented, and the binder resin particles and the colorant particles are easily aggregated in the aggregation step. When the number average particle diameter is within the above range, uneven distribution between toners is reduced, dispersion in the toner is improved, and variation in performance and reliability is reduced.

In the emulsion aggregation method, a wax particle dispersion may be used as needed. The wax particle dispersion is obtained by dispersing at least wax particles in a dispersant. The number average particle diameter of the wax particles is preferably 2.0 μm or less, and more preferably 1.0 μm or less. When the number average particle diameter is 2.0 μm or less, the deviation in wax content between toner particles is small, and long-term image stability is improved. When the number average particle diameter is within the above range, uneven distribution between toners is reduced, dispersion in the toner is improved, and variation in performance and reliability is reduced.

The combination of the colorant particles, the binder resin particles, and the wax particles is not particularly limited, and may be appropriately selected depending on the purpose.

In addition to the above-described dispersion liquid, other particle dispersion liquids obtained by dispersing appropriately selected particles in a dispersing agent may be further mixed.

The particles contained in the other particle dispersion liquid are not particularly limited, and may be appropriately selected according to purpose. Examples thereof include internal additive particles, charge control agent particles, inorganic particles, and abrasive particles. These particles may be dispersed in a binder particle dispersion or a colorant particle dispersion.

Examples of the dispersant contained in the binder resin particle dispersion, the colorant particle dispersion, the wax fine particle dispersion, and other particle dispersions include aqueous media containing a polar surfactant. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of 1 or more than 2. The content of the polar surfactant cannot be specified roughly, and can be appropriately selected according to the purpose.

Examples of the polar surfactant include anionic surfactants such as sulfate and salt systems, sulfonate systems, phosphate systems, soap systems, and the like; cationic surfactants such as amine salts and quaternary ammonium salts; etc.

Specific examples of the anionic surfactant include sodium dodecylbenzene sulfonate, sodium dodecylsulfate, sodium alkylnaphthalene sulfonate, sodium dialkylsulfosuccinate, and the like.

Specific examples of the cationic surfactant include alkyl xylyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride, and the like. These may be used alone or in combination of 1 or more than 2.

These polar surfactants may be used in combination with nonpolar surfactants. Examples of the nonpolar surfactant include nonionic surfactants based on polyethylene glycol, alkylphenol ethylene oxide adducts, and polyols.

The content of the colorant particles is preferably 0.1 parts by mass to 30 parts by mass with respect to 100 parts by mass of the binder resin in the aggregated particle dispersion when the aggregated particles are formed.

The content of the wax particles is preferably 0.5 to 25 parts by mass, and more preferably 5 to 20 parts by mass, relative to 100 parts by mass of the binder resin in the aggregated particle dispersion when the aggregated particles are formed.

Further, in order to more specifically control the charging performance of the obtained toner, the charge control particles and the binder resin particles may be added after the formation of the aggregated particles.

Particle diameters of particles such as binder resin particles and colorant particles were measured using a laser diffraction/scattering particle diameter distribution analyzer LA-920 manufactured by HORIBA, ltd.

(Aggregation step)

The aggregation step is performed to form aggregated particles including binder resin particles and, if necessary, colorant particles, wax particles, and the like, in an aqueous medium including the binder resin particles and, if necessary, colorant particles, wax particles, and the like.

For example, by adding and mixing a pH adjuster, an aggregating agent, and a stabilizer to an aqueous medium, and appropriately adjusting the temperature, mechanical power, and the like, aggregated particles can be formed in the aqueous medium.

Examples of the pH adjuster include bases such as ammonia and sodium hydroxide, and acids such as nitric acid and citric acid. Examples of the coagulant include salts of monovalent metals such as sodium and potassium; salts of divalent metals such as calcium and magnesium; salts of trivalent metals such as iron and aluminum; and alcohols such as methanol, ethanol, and propanol.

Examples of the stabilizer mainly include the polar surfactant itself or an aqueous medium containing the same. For example, when the polar surfactant contained in each particle dispersion is anionic, a cationic surfactant may be selected as the stabilizer.

The addition/mixing of the coagulant or the like is preferably performed at a temperature equal to or lower than the glass transition temperature of the resin contained in the aqueous medium. When mixing is performed under such temperature conditions, aggregation proceeds in a stable state. The mixing may be performed using, for example, a known mixing device, a homogenizer, a mixer, or the like.

In the aggregation step, the second binder resin particles are adhered to the surfaces of the aggregated particles using a binder resin particle dispersion liquid containing the second binder resin particles to form a coating layer (shell layer), whereby toner particles having a core/shell structure in which a shell layer is formed on the surfaces of the core particles can be obtained.

The second binder resin particles used in this case may be the same as or different from the binder resin particles constituting the core particles. In addition, the aggregation step may be repeatedly performed a plurality of times in steps.

(Fusion step)

The fusing step is a step of heating and fusing the obtained aggregated particles. Before the transition to the fusing step, a pH adjuster, a polar surfactant, a nonpolar surfactant, or the like may be appropriately charged to prevent fusion between toner particles.

The heating temperature may be a glass transition temperature of the resin contained in the aggregated particles (when there are two or more kinds of resins, the glass transition temperature of the resin having the highest glass transition temperature) to a decomposition temperature of the resin. Therefore, the heating temperature differs depending on the type of resin of the binder resin particles, and cannot be specified roughly, but it is common that the glass transition temperature of the resin contained in the aggregated particles is to 140 ℃. In addition, heating may be performed using a known heating device/appliance.

As the fusion time, if the heating temperature is high, a short time is sufficient, and if the heating temperature is low, a long time is required. That is, the fusion time depends on the heating temperature and cannot be specified in general, but is generally 30 minutes to 10 hours.

The toner particles obtained by each of the steps described above may be subjected to solid-liquid separation according to a known method, and the toner particles may be recovered, and then washed, dried, and the like under appropriate conditions.

(External addition step)

The toner can be obtained by adding spherical silica particles and hydrotalcite particles to the obtained toner particles.

[ Binder resin ]

As the binder resin, the following polymer or resin including amorphous polyester may be used.

For example, monomers of styrene and substituted styrenes such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene can be used; styrenic copolymers such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-alpha-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinylmethyl ketone copolymer and styrene-acrylonitrile-indene copolymer; and polyvinyl chloride, phenolic resin, natural resin modified maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone-indene resin, and petroleum-based resin.

Amorphous polyesters are resins having a "polyester structure" in the binder resin chain. Specifically, the components constituting the polyester structure include alcohol monomer components of two or more, and acid monomer components such as carboxylic acids of two or more, carboxylic anhydrides of two or more, carboxylic esters of two or more, and the like.

The following are examples of alcohol monomer components of two or more elements: bisphenol A alkylene oxide adducts such as polyoxypropylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2, 2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2, 2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2, 2-bis (4-hydroxyphenyl) propane and polyoxypropylene (6) -2, 2-bis (4-hydroxyphenyl) propane, and ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3, 6-hexanetriol, 1, 4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2, 4-butanetriol, 1,2, 5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1, 2, 4-propanediol, trimethylol, 1, 3-propanediol, and the like.

Among these, the aromatic diol may be preferably used as the alcohol monomer component, and the aromatic diol is preferably contained in an amount of 80 mol% or more in the alcohol monomer component constituting the polyester resin.

The following are examples of acid monomer components, such as dicarboxylic acids or more, carboxylic anhydrides or more, and carboxylic esters or more: aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; c _6-18 alkyl or alkenyl substituted succinic acids or their anhydrides; and unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid, or anhydrides thereof.

Among these, acid monomer components that can be preferably used include polycarboxylic acids such as terephthalic acid, succinic acid, adipic acid, fumaric acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, and anhydrides thereof.

In addition, from the viewpoint of the stability of the frictional charge amount, the acid value of the polyester resin is preferably 1mgKOH/g to 50mgKOH/g.

The acid value can be kept within this range by adjusting the type and compounding amount of the monomer used in the resin. Specifically, it can be controlled by adjusting the ratio and molecular weight of the alcohol monomer component and the acid monomer component at the time of resin production. It can also be controlled after polycondensation of the ester by reacting the terminal alcohol with a polyacid monomer, such as trimellitic acid.

Crystalline polyesters may be used as binder resins.

[ Colorant ]

The toner particles may also contain a colorant. Examples of colorants are as follows.

Examples of the black colorant include carbon black, and black colorants obtained by blending yellow, magenta, and cyan colorants to adjust the color. Pigments may be used alone as the colorant, but from the viewpoint of image quality of full-color images, it is preferable to use both dyes and pigments to improve color definition.

Examples of magenta pigments include c.i. pigment red 1、2、3、4、5、6、7、8、9、10、11、12、13、14、15、16、17、18、19、21、22、23、30、31、32、37、38、39、40、41、48：2、48：3、48：4、49、50、51、52、53、54、55、57：1、58、60、63、64、68、81：1、83、87、88、89、90、112、114、122、123、146、147、150、163、184、202、206、207、209、238、269、282;C.I. pigment violet 19; c.i. vat red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of magenta dyes include c.i. solvent red 1,3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; c.i. disperse red 9; c.i. solvent violet 8, 13, 14, 21, 27; oil-soluble dyes, such as c.i. disperse violet 1; and basic dyes such as c.i. basic red 1,2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39 and 40 and c.i. basic violet 1,3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of cyan pigments include c.i. pigment blue 2,3, 15: 2. 15: 3. 15: 4. 16 and 17; c.i. vat blue 6; c.i. acid blue 45, and copper phthalocyanine pigment having 1 to 5 phthalimidomethyl substituents on the phthalocyanine skeleton.

Examples of cyan dyes include c.i. solvent blue 70.

Examples of yellow pigments include c.i. pigment yellow 1、2、3、4、5、6、7、10、11、12、13、14、15、16、17、23、62、65、73、74、83、93、94、95、97、109、110、111、120、127、128、129、147、151、154、155、168、174、175、176、180、181、185;C.I. vat yellow 1,3, 20.

Examples of yellow dyes include c.i. solvent yellow 162.

The content of the colorant is preferably 0.1 part by mass to 30 parts by mass with respect to 100 parts by mass of the binder resin.

[ Wax ]

Waxes may also be used in the toner particles. The wax is not particularly limited, and examples of the wax include the following: hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline waxes, paraffin waxes and fischer-tropsch waxes; hydrocarbon wax oxides, such as polyethylene oxide waxes, and block copolymers thereof; waxes consisting essentially of fatty acid esters, such as carnauba wax; and partially or fully deoxygenated fatty acid esters, such as deoxygenated carnauba wax.

Other examples include the following: saturated linear fatty acids such as palmitic acid, stearic acid and montanic acid; unsaturated fatty acids such as brasilenic acid, eleostearic acid and stearidonic acid; saturated alcohols, such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauba alcohol, serinol, and melissa alcohol; polyols, such as sorbitol; esters of fatty acids such as palmitic acid, stearic acid, behenic acid and montanic acid with alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, vanillyl alcohol, serinol and melam alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; saturated fatty acid bisamides, for example methylene bis stearamide, ethylene bis capric acid amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide; unsaturated fatty acid amides such as ethylene bis-oleamide, hexamethylene bis-oleamide, N '-dioleyladipamide and N, N' -dioleylsebacamide; aromatic bisamides, such as m-xylyl bisstearamide and N, N' -distearyl isophthalic acid amide; aliphatic metal salts (commonly referred to as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; aliphatic hydrocarbon waxes grafted with vinyl monomers such as styrene or acrylic acid; partially esterified products of fatty acids and polyols, such as glyceryl behenate; and methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and fats.

Among these waxes, hydrocarbon waxes such as paraffin wax and fischer-tropsch wax are preferable from the viewpoints of improving low-temperature fixability and fixing entanglement resistance.

The content of the wax is preferably 0.5 to 25 parts by mass with respect to 100 parts by mass of the binder resin.

Further, from the viewpoint of achieving both the storage stability and the high-temperature offset resistance of the toner, in the endothermic curve at the time of temperature increase measured by a Differential Scanning Calorimeter (DSC), the peak temperature of the maximum endothermic peak present in the range of 30 ℃ to 200 ℃ is preferably 50 ℃ to 110 ℃.

[ Charge control agent ]

The toner may include a charge control agent as needed. A known charge control agent may be used in the toner, but a metal compound of an aromatic carboxylic acid is particularly desirable because it is colorless and produces toner particles having a high charging speed and capable of stably maintaining a certain charge amount.

Examples of the negatively chargeable charge control agent include a salicylic acid metal compound, a naphthoic acid metal compound, a dicarboxylic acid metal compound, a polymer compound having a sulfonic acid or carboxylic acid in a side chain, a polymer compound having a sulfonate or sulfonate in a side chain, a polymer compound having a carboxylate or carboxylate in a side chain, and a boron compound, a urea compound, a silicon compound, and calixarene.

The charge control agent may be added to the toner base particle from the inside or the outside. The addition amount of the charge control agent is preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

The toner may be mixed with a magnetic carrier and used as a two-component developer to obtain a stable image for a long period of time.

Examples of the magnetic carrier include known carriers such as magnetic bodies, e.g., surface-oxidized iron powder, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earth metals, alloy particles thereof, oxide particles, ferrite, and the like, and magnetic-body-dispersed resin carriers (so-called resin carriers) containing a magnetic body and a binder resin holding the magnetic body in a dispersed state.

Hereinafter, a method for measuring values of respective physical properties according to the present invention will be described.

< Method for measuring number average particle diameter (Da, db) of spherical silica particles and hydrotalcite particles >

The number average particle diameters (Da, db) of the spherical silica particles and hydrotalcite particles were measured as follows.

An image of the surface of the toner particle was taken with FE-SEM S-4800 (Hitachi, manufactured by Ltd.) at 100000 magnification. Using the magnified image, the particle diameters of 100 or more spherical silica particles and hydrotalcite particles were measured, and the number average particle diameters (Da, db) of the spherical silica particles and hydrotalcite particles were determined by arithmetic average.

When the shape is spherical, the absolute maximum length is taken as the particle diameter, and when the particles have a long axis and a short axis, the long axis is taken as the particle diameter. Whether the silica particles are spherical or not can be judged by measurement according to the measurement of circularity described later.

Further, hydrotalcite particles on the surface of toner particles can be distinguished by the following method.

(Method for identifying hydrotalcite particles)

Hydrotalcite particles can be identified by a combination of shape observation with a Scanning Electron Microscope (SEM) and by elemental analysis with energy dispersive X-ray analysis (EDS).

Using S-4800, focus was adjusted on the toner particle surface, and the external additive to be discriminated was observed. By performing EDS analysis on the external additive to be discriminated, hydrotalcite particles can be identified from the presence or absence of elemental peaks.

When the elemental peak of at least one metal selected from the group consisting of Mg, zn, ca, ba, ni, sr, cu and Fe and the elemental peak of at least one metal selected from the group consisting of Al, B, ga, fe, co and In (these are metals that can constitute hydrotalcite particles) are observed as elemental peaks, the presence of hydrotalcite particles containing both types of metals can be inferred.

Samples of hydrotalcite particles deduced from EDS analysis were prepared separately, and shape observation by SEM and EDS analysis were performed. Whether the analysis result of the sample is matched with the analysis result of the particles to be distinguished is determined by comparison, and whether the particles are hydrotalcite particles is judged.

In addition, when spherical silica particles or hydrotalcite particles before external addition are available, the number average particle diameter can be calculated by the aforementioned method by using the above particles.

< Method for measuring the circularity of spherical silica particles >

To measure the circularity of the spherical particles, calculations were performed by using image analysis software ImageJ (developed by WAYNE RASHAND) to analyze the toner surface observation image taken by Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (HITACHI HIGH-Technologies Corporation). The measurement procedure is as follows.

(1) Sample preparation

A thin layer of conductive paste was applied on a sample stage (aluminum sample stage 15mm x 6 mm) and toner was deposited thereon. The excess toner is blown using a blower, and then sufficiently dried. The sample stage is placed on a sample holder.

(2) S-4800 viewing Condition

The observation conditions are shown below.

Acceleration voltage: 0.8kV

Emission current: 20 mu A

A detector: [ SE (U) ], [ +BSE (L.A.100) ]

Probe current: [ Normal ]

Focusing mode: [ UHR ]

WD：[3.0mm]

(3) Image storage

Brightness is adjusted in the ABC mode, and an image of 640×480 pixels in size is photographed and saved. The following analysis was performed using the image file. At this time, a relatively flat portion of the toner surface (the field of view in which the entire observation surface is in focus) is selected to obtain an image. The observation magnification is appropriately adjusted according to the size of the fine particles as the observation target.

(4) Image analysis

From the obtained SEM observation images, circularity was calculated using image processing software ImageJ (developed by WAYNE RASHAND). The calculation steps are as follows.

[1] The ratio was Set by [ analysis ] - [ Set ratio (Set Scale) ].

[2] The threshold is set with [ image ] - [ adjustment ] - [ threshold ].

(Set to a value at which noise does not remain and inorganic fine particles to be measured remain.)

[3] In [ image ] - [ Crop ], the measured image portion of the inorganic fine particles is selected.

[4] Overlapping particles are deleted by image editing.

[5] The black and white image is inverted with [ edit ] - [ inversion (invite) ].

[6] Check [ area ] and [ shape descriptor ] with [ analysis ] - [ setup measure ]. In addition, in the case of the optical fiber,

Setting [ Redirect to ] as [ None ], and

The [ decimal place (0-9) ] is set to 3.

[7] The area of the particles was designated to be 0.0003 μm ² or more, and analysis was performed using [ analysis ] - [ analysis particles ].

[8] The circularity value of each particle was obtained.

[9] More than 100 observed particles were measured and the arithmetic mean of the circularities obtained was calculated to obtain circularities.

For toner containing a plurality of fine particles on the surface of toner particles, measurement can be performed in the same manner. When a reflected electron image is observed in S-4800, the element analysis such as EDAX can be used to specify the element of each fine particle. In addition, the same kind of fine particles may be selected according to shape characteristics and the like. By performing the above measurement on the same kind of fine particles, the circularity of various kinds of fine particles can be calculated. Similarly, the above number average particle diameter (Da, db) measurement can be performed for various fine particles.

When spherical silica particles before external addition can be obtained, the circularity can be calculated by the above-described method by using such particles.

< Method for measuring weight average particle diameter (D4) of toner >

The weight average particle diameter (D4) of the toner is calculated as follows. As the measuring device, a precision particle size distribution measuring device "Coulter counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, inc.) equipped with a 100 μm mouth tube was used. To set measurement conditions and analyze measurement data, special software "Beckman Coulter Multisizer version 3.51" (manufactured by Beckman Coulter, inc.) attached to the device was used.

Measurements were made with 25000 valid measurement channels. As the electrolytic aqueous solution for measurement, a solution obtained by dissolving extra sodium chloride in ion-exchanged water to a concentration of about 1 mass%, for example, "ISOTON II" (manufactured by Beckman Coulter, inc.) can be used.

< Measurement of fixation Rate of spherical silica particles >

(Washing step)

In a 50mL vial, 20g of a 30% by mass aqueous solution of "CONTAMINON N" (neutral detergent for washing precision measuring instruments, consisting of nonionic surfactant, anionic surfactant and organic builder and having a pH of 7) was weighed and mixed with 1g of toner.

The mixture was set to "KM Shaker" (model: v.sx) manufactured by Iwaki Sangyo co., ltd. And vibrated for 120 seconds at a set speed of 50. As a result, the spherical silica particles move from the toner particle surface to the dispersion liquid side depending on the fixation state of the spherical silica particles.

Thereafter, the toner and spherical silica particles transferred to the supernatant were separated with a centrifugal separator (H-9R; manufactured by Kokusan co., ltd.) for 5 minutes at 16.67S ^-1.

The precipitated toner was dried by vacuum drying (40 ℃/24 hours), and washed with water to obtain a toner.

Next, an image of the toner obtained by the water washing step (the toner after water washing) was photographed using a hitachi ultra-high resolution field emission scanning electron microscope S-4800 (HITACHI HIGH-Technologies Corporation).

Then, the photographed toner surface Image was analyzed with Image analysis software Image-Pro Plus ver.5.0 (Nippon Roper co., ltd.) and the fixation ratio was calculated.

The image capturing conditions for S-4800 are as follows.

(1) Sample preparation

Tu Baoceng conductive paste was applied on a sample stage (aluminum sample stage 15mm×6 mm) and toner was deposited thereon. The excess toner is blown using a blower, and then sufficiently dried. The sample stage was placed on a sample holder and the height of the sample stage was adjusted to 36mm with a sample altimeter.

(2) S-4800 viewing condition set

In the measurement of the fixation ratio, elemental analysis by the above-described energy dispersive X-ray analysis (EDS) is performed in advance, and the measurement is performed after distinguishing spherical silica particles on the toner particle surface.

Liquid nitrogen was poured into an anti-fouling trap attached to the housing of S-4800 until spilled, and left for 30 minutes. The [ PC-SEM ] of S-4800 was started for flushing (purging of the FE chip electron source). Clicking the acceleration voltage display portion of the control panel on the image, and pressing the [ flush ] button opens the flush execution dialog. This operation is performed after confirming that the flush strength is 2. The emission current from the wash was then confirmed to be 20 to 40. Mu.A. The sample holder is inserted into the sample chamber of the S-4800 housing. The [ origin ] on the control panel is pressed to transfer the sample holder to the viewing position.

The accelerating voltage display section is clicked to open the HV setting dialog, and the accelerating voltage is set to [1.1kV ] and the emission current is set to [20 μa ]. In the [ basic ] tab of the operation panel, the signal selection is set to [ SE ], the [ upper (U) ] and [ +bse ] are selected as SE detectors, and the [ l.a.100] is selected with a selection button on the right side of [ +bse ] to set the back-scattered electron imaging mode. In the same [ basic ] tag of the operation panel, the probe current of the electron optical system condition block is set to [ normal ], the focus mode is set to [ UHR ], and WD is set to [4.5mm ]. The [ ON ] button of the accelerating voltage display section ON the control panel is pressed to apply the accelerating voltage.

(3) Calculation of number average particle diameter (D1) of toner

The magnification is set to 5000 (5 k) times by dragging in the enlarged display portion of the control panel. The focus knob [ COARSE ] on the operation panel is rotated, and the aperture alignment is adjusted when the focus reaches a certain degree. Click on [ Align ] on the control panel to display an Align dialog and select [ beam ]. STIGMA/align knob (X, Y) on the operation panel is rotated to move the displayed light beam to the center of the concentric circles. Next, select [ aperture ], and rotate STIGMA/align knob (X, Y) one by one to stop the movement of the image or to adjust the image movement to a minimum. The aperture dialog is closed and focusing is performed with autofocus. This operation was repeated twice again to focus.

Thereafter, the particle diameters of 300 toner particles were measured to determine a number average particle diameter (D1). The particle diameter of each particle is the maximum diameter when the toner particles are observed.

(4) Focus adjustment

For the particles having diameters within the number average particle diameter (D1) ±0.1 μm obtained in (3), the magnification was set to 10000 (10 k) times by dragging in the enlarged display portion of the control panel in a state where the midpoint of the maximum diameter was aligned with the center of the measurement screen.

The focus knob [ COARSE ] on the operation panel is rotated, and the aperture alignment is adjusted when the focus reaches a certain degree. Click on [ Align ] on the control panel to display an alignment dialog and select [ beam ]. STIGMA/align knob (X, Y) on the operation panel is rotated to move the displayed light beam to the center of the concentric circles.

Next, select [ aperture ], and rotate STIGMA/align knob (X, Y) one by one to stop the movement of the image or to adjust the image movement to a minimum. The aperture dialog is closed and focusing is performed with autofocus.

Thereafter, the magnification is set to 50000 (50 k) times, focusing is adjusted using the focus knob and STIGMA/align knob in the same manner as described above, and focusing is adjusted again by auto-focusing. This operation is repeated again to focus. Here, since the measurement accuracy of the coverage tends to be low when the inclination angle of the observation surface is large, a mode in which focusing is performed simultaneously on the entire observation surface when focusing is adjusted is selected, whereby analysis is performed by selecting the smallest possible surface inclination.

(5) Image storage

Brightness was adjusted in ABC mode, and images were taken with a size of 640 x 480 pixels and saved. The following analysis was performed using the image file. One photograph was taken for one toner particle, and an image was obtained for 25 toner particles.

(6) Image analysis

The fixation ratio was calculated by binarizing the image obtained by the above method by using the following analysis software. At this time, analysis was performed by dividing the screen into 12 squares.

The analysis conditions for Image-Pro Plus ver.5.0 of the Image analysis software are as follows. However, when the number average particle diameter of the added external additive is unknown, the measurement object is excluded according to the particle diameter as described below. When silica particles having a particle diameter of less than 10nm and spherical silica particles having a particle diameter of more than 40nm are included in the divided portion, the fixation ratio is not calculated in the portion.

Sequentially select [ count/size ] and [ option ] from [ measure ] in the toolbar, and set a binarization condition. In the split option (Segmentation Options), 8-connected and smoothing is set to 0. In addition, screening, filling the holes, and envelope were not selected, and [ excluding boundary lines ] was set to [ none ]. From the [ measurement ] on the toolbar, the [ measurement item ] is selected, and 2-10 ⁷ is input as the range of the filter range area.

The fixation rate was calculated by surrounding square areas. At this time, the area (C) of the setting region is 24000 pixels to 26000 pixels. In [ treatment ] -binarization, automatic binarization was performed, and the total area (D) of the region without spherical silica particles was calculated.

From the area C of the square region and the total area D of the region without spherical silica particles, the fixation ratio was obtained by the following formula.

Area (%) =100- (D/c×100) where spherical silica particles are present

By performing the above analysis on the toner before and after washing with water, the fixation rate of the spherical silica particles can be obtained from the following formula.

Fixation ratio (%) = (region where spherical silica particles exist in toner after washing/region where spherical silica particles exist in toner before washing) ×100

The arithmetic average of all the obtained data was taken as the fixation ratio.

< Measurement of the fixation Rate of hydrotalcite particles >

After identifying the hydrotalcite particles, the fixation rate of the hydrotalcite particles was measured as described in the determination methods of the number average particle diameters (Da, db) of the spherical silica particles and the hydrotalcite particles.

First, preparation of a sample was performed as follows.

Toner before washing with water: the toner to be measured was used as it is.

Toner after washing with water: 160g of sucrose (manufactured by KISHIDA CHEMICAL co., ltd.) was added to 100mL of ion-exchanged water and dissolved by heating in a water bath to prepare a sucrose concentrate. Then, 31g of a sucrose concentrate and 6mL of CONTAMINON N (10 mass% of an aqueous solution of a neutral detergent for washing a precision measuring instrument, which includes a nonionic surfactant, an anionic surfactant, and an organic builder, and has a pH of 7; manufactured by Wako Pure Chemical Industries, ltd.) were placed in a centrifuge tube to prepare a dispersion. A total of 1g of toner was added to the dispersion liquid, and the toner patch was loosened with a spatula or the like.

The centrifuge tube was set to "KM Shaker" (model: v.sx) manufactured by Iwaki Sangyo co., ltd. And vibrated at a set speed of 50 for 120 seconds. After shaking, the solution was transferred to a glass tube (50 mL) for a swinging rotor, and the toner and the external additive transferred to the supernatant were separated with a centrifugal separator (H-9R; manufactured by Kokusan co., ltd.) (at 16.67S ^-1 for 5 minutes).

After it is visually confirmed that the toner and the aqueous solution are sufficiently separated, the toner separated at the uppermost layer is collected with a spatula or the like. The aqueous solution including the collected toner was filtered with a vacuum filter, and then dried with a dryer for more than 1 hour to prepare a sample.

For these samples before and after washing, the fixation rate was determined by using the intensity of the target element by wavelength dispersive X-ray fluorescence analysis (XRF).

About 1g of the toner after washing with water or the toner before washing with water was put into a dedicated aluminum ring for pressing and flattened, and was pressurized at 20MPa for 60 seconds by using a lozenge-forming compressor [ BRE-32] (MAEKAWA TEST Instruments co., ltd.) to obtain pellets formed to a thickness of about 2mm, and the pellets were used as measurement samples.

As the measuring means, a wavelength-dispersive fluorescent X-ray analyzer [ Axios ] (manufactured by PANalytical) and its attached dedicated software [ SuperQ ver.4.0f ] (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data were used. Rh was used as the anode of the X-ray tube, the measuring atmosphere was vacuum, the measuring diameter (collimator mask diameter) was 10mm, and the measuring time was 10 seconds. Further, a Proportional Counter (PC) is used for detection when measuring light elements, and a Scintillation Counter (SC) is used when measuring heavy elements. The measurement was performed under the above conditions, the element was identified based on the obtained X-ray peak position, and the concentration thereof was calculated from the count rate (unit: cps) which is the number of X-ray photons per unit time.

Regarding the fixation ratio from the toner, first, the elemental strength of the toner before washing and the toner after washing was obtained by the above-described method. Thereafter, the fixation ratio was calculated based on the following formula.

As an example, a formula in which Mg is used as a target element in hydrotalcite particles is shown.

Formula (Kb%) of fixation ratio of hydrotalcite particles= (strength of Mg element of toner after washing)/(strength of Mg element of toner before washing) ×100

< Measurement of content of spherical silica particles and hydrotalcite particles >

The content of spherical silica particles and hydrotalcite particles was obtained by calculation from the intensities of metal elements derived from spherical silica particles and hydrotalcite particles in a toner measured with an X-ray fluorescence analyzer (XRF).

For example, in the following examples, the content of spherical silica particles and the content of hydrotalcite particles may be analyzed and calculated from the Si element strength and Mg element strength, respectively, using a calibration curve method.

Examples

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples, all "parts" are based on mass unless otherwise specified.

< Production example of spherical silica particles 1>

A total of 500 parts of methanol and 70 parts of water adjusted to pH 5.4 using 10 mass% hydrochloric acid were added and mixed in a 1.5L glass reaction vessel equipped with a stirrer, a dropping nozzle, and a thermometer to obtain a catalyst solution. After the catalyst solution was adjusted to 30 ℃, 100 parts of Tetramethoxysilane (TMOS) and 20 parts of 8.0 mass% aqueous ammonia were simultaneously dropped over 60 minutes while stirring to obtain a hydrophilic silica fine particle dispersion.

Thereafter, the obtained silica particle dispersion was concentrated to a solid content concentration of 40 mass% with a rotary filter R-Fine (manufactured by Kotobuki Industries co., ltd.) to obtain a silica particle dispersion.

A total of 50 parts of Hexamethyldisilazane (HMDS) as a hydrophobizing agent was added to 250 parts of the silica particle dispersion, the reaction was performed at 130 ℃ for 2 hours, and the reaction product was cooled and dried by spray drying to obtain spherical silica particles 1. Table 1 shows the physical properties of the obtained spherical silica particles 1.

< Production of spherical silica particles 2 to 4 and comparative particles 1 to 2 >

Spherical silica fine particles 2 to 4 and comparative particles 1 to 2 were produced in the same manner as the spherical silica fine particles 1 except that some of the production conditions of the spherical silica fine particles 1 were changed to the reaction conditions shown in table 1. Table 1 shows the physical properties.

< Comparative particle 3>

"NX-90G" manufactured by Nippon Aerosil Co., ltd. Was used as comparative particle 3. Table 1 shows the physical properties.

TABLE 1

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< Production example of hydrotalcite particles 1 >

A total of 203.3g of magnesium chloride hexahydrate and 96.6g of aluminum chloride hexahydrate were dissolved in 1L of deionized water, and the pH of the solution was adjusted to 10.5 with a solution obtained by dissolving 60g of sodium hydroxide in 1L of deionized water while maintaining the temperature at 25 ℃. The solution was then cured at 98℃for 24 hours.

After cooling, the precipitate was washed with deionized water until the conductivity of the filtrate reached 100. Mu.S/cm or less, to obtain a slurry having a concentration of 5% by mass. While stirring the slurry, spray drying was performed with a spray dryer (DL-41,Yamato Scientific Co, manufactured by ltd.) at a drying temperature of 180 ℃, a spray pressure of 0.16MPa, and a spray speed of about 150mL/min to obtain hydrotalcite particles 1. Table 2 shows the physical properties of the obtained hydrotalcite particles 1.

< Production examples of hydrotalcite particles 2 to 5>

Hydrotalcite particles 2 to 5 were prepared in the same manner as hydrotalcite particles 1 by appropriately adjusting the amounts of raw materials and reaction conditions. Table 2 shows the physical properties.

TABLE 2

Particles	Species of type	Number average particle diameter Db (nm)
			Hydrotalcite particles 1	Hydrotalcite (hydrotalcite)	280
Hydrotalcite particles 2	Hydrotalcite (hydrotalcite)	320
			Hydrotalcite particles 3	Hydrotalcite (hydrotalcite)	225
Hydrotalcite particles 4	Hydrotalcite (hydrotalcite)	200
			Hydrotalcite particles 5	Hydrotalcite (hydrotalcite)	400

< Production example of polyester resin 1 >

In a reactor equipped with a stirrer, a thermometer and a cooler for outflow, 20 parts of propylene oxide-modified bisphenol a (2 mol adduct), 80 parts of propylene oxide-modified bisphenol a (3 mol adduct), 20 parts of terephthalic acid, 20 parts of isophthalic acid and 0.50 part of titanium tetrabutoxide were added, and an esterification reaction was carried out at 190 ℃.

Thereafter, 1 part of trimellitic anhydride (TMA) was added, the temperature was increased to 220 ℃ and the pressure inside the system was gradually lowered, and polycondensation reaction was performed at 150Pa to obtain polyester resin 1. The acid value of the polyester resin 1 was 12mgKOH/g, and the softening point was 110 ℃.

(Preparation of polyester resin particle Dispersion)

1 Part of polyester resin

500 Parts of ion-exchanged water

The above materials were placed in a stainless steel vessel, heated to 95 ℃ in a hot bath and melted, and 0.1mol/L sodium bicarbonate was added to increase the pH to greater than 7.0 while stirring thoroughly at 7800rpm using a homogenizer (manufactured by IKA: ultra Turrax T50). Thereafter, a mixed solution of 3 parts of sodium dodecylbenzenesulfonate and 297 parts of ion-exchanged water was gradually added dropwise, and emulsification and dispersion were performed to obtain a polyester resin particle dispersion 1.

When the particle size distribution of the polyester resin particle dispersion 1 was measured using a particle size measuring device (LA-920, manufactured by Horiba, ltd.). In addition, coarse particles exceeding 1 μm were not observed.

(Preparation of wax particle Dispersion)

500 Parts of ion-exchanged water

250 Parts of wax (hydrocarbon wax; peak endotherm maximum temperature 77 ℃ C.)

The above materials were placed in a stainless steel vessel, heated to 95 ℃ in a hot bath and melted, and 0.1mol/L sodium bicarbonate was added to increase the pH to greater than 7.0 while stirring thoroughly at 7800rpm using a homogenizer (manufactured by IKA: ultra Turrax T50).

Thereafter, a mixed solution of 5 parts of sodium dodecylbenzenesulfonate and 245 parts of ion-exchanged water was gradually added dropwise, and emulsification and dispersion were performed. When the particle size distribution of the wax particles contained in the wax particle dispersion was measured using a particle size measuring device (LA-920, manufactured by Horiba, ltd.). In addition, coarse particles exceeding 1 μm were not observed.

(Preparation of colorant particle Dispersion 1)

C.I. pigment blue 15:3 100 parts

5 Parts of sodium dodecyl benzene sulfonate

400 Parts of ion-exchanged water

The above materials were mixed and dispersed using a sand mill. When the particle size distribution of the colorant particles contained in the colorant particle dispersion was measured using a particle size measuring device (LA-920, manufactured by Horiba, ltd.). In addition, coarse particles exceeding 1 μm were not observed.

< Production example of toner particle 1 >

The polyester resin particle dispersion 1, the wax particle dispersion and sodium dodecylbenzenesulfonate were charged into a reactor (flask having a volume of 1 liter, anchor blades with baffles) and uniformly mixed. Meanwhile, the colorant particle dispersion 1 was uniformly mixed in a 500mL beaker, and the mixture was gradually added to the reactor while stirring to obtain a mixed dispersion. While stirring the resulting mixed dispersion, an aqueous aluminum sulfate solution was dropped in an amount of 0.5 parts in total in terms of solid content to form aggregated particles.

After completion of the dripping, the system was replaced with nitrogen, kept at 50℃for 1 hour, and further kept at 55℃for 1 hour.

The temperature was then raised and maintained at 90℃for 30 minutes. Thereafter, the temperature was lowered to 63 ℃ and maintained for 3 hours to form molten particles. The reaction at this time was carried out under a nitrogen atmosphere. After a predetermined time, cooling is performed at a rate of 0.5 ℃ per minute until the temperature reaches room temperature.

After cooling, the reaction product was subjected to solid-liquid separation with a pressure filter having a volume of 10L at a pressure of 0.4MPa to obtain a toner cake. Thereafter, ion-exchanged water was added to fill the pressure filter with water, and washing was performed at a pressure of 0.4 MPa. Further, the same washing was performed 3 times in total. Thereafter, solid-liquid separation was performed at a pressure of 0.4MPa, and fluidized bed drying was performed at 45 ℃ to obtain toner particles 1. Table 3 shows the physical properties of the toner particles 1 thus obtained.

< Production example of toner particles 2 >

Polyester resin A (terephthalic acid: isophthalic acid: propylene oxide-modified bisphenol A (2 mol adduct): polycondensate of ethylene oxide-modified bisphenol A (2 mol adduct) =20:20:44:50 (mass ratio); mw=7000, mn=3200, tg=57 ℃ C.) 45.0 parts

Polyester resin B (terephthalic acid: trimellitic acid: propylene oxide modified bisphenol A (2 mol adduct): polycondensate of ethylene oxide modified bisphenol A (2 mol adduct) =24:3:70:2 (mass ratio),

(0.10 Parts per 100 parts of the total of the polyester resins A and B)

The above materials were dispersed using a mill (manufactured by Mitsui Kinzoku co., ltd.) for 3 hours and left standing for 72 hours to obtain a mixed colorant dispersion.

Meanwhile, after 17 parts of sodium phosphate was added to 220 parts of ion-exchanged water and heated to 60 ℃, 20 parts of 1.0mol/L aqueous CaCl ₂ solution was gradually added to obtain an aqueous medium including a calcium phosphate compound.

The colorant dispersion was poured into an aqueous medium and stirred with a TK homomixer at a temperature of 65 ℃ in an N ₂ atmosphere at 12000rpm for 15 minutes to granulate the colorant dispersion. Thereafter, the TK homomixer was replaced with a usual propeller type stirring device, the rotation speed of the stirring device was maintained at 150rpm, the internal temperature was raised to 95 ℃ and maintained for 3 hours to remove the solvent, and an aqueous medium in which the resin particles were dispersed was obtained.

Hydrochloric acid was added to the aqueous medium in which the resin particles were dispersed to adjust the pH to 1.4, and calcium phosphate was dissolved by stirring for 1 hour. The dispersion was filtered with a pressure filter, and the resulting wet toner particles were washed to obtain a toner cake. Thereafter, the toner cake is pulverized and dried to obtain toner particles 2. Table 3 shows the physical properties of the obtained toner particles 2.

TABLE 3

Particles	Weight average particle diameter D4 (μm)	Method of manufacture
			Toner particles 1	6.0	Emulsion aggregation
Toner particles 2	6.0	Dissolving suspension

< Production example of toner 1 >

Spherical silica particles 1 (1.0 part) and hydrotalcite particles 1 (0.5 part) were externally added to the obtained toner particles 1 (100 parts), and mixed with FM10C (manufactured by Nippon Coke Industries, ltd.). The external addition conditions were as follows: loading of toner particles: 2.0kg, rotational speed: 66.6s ^-1, external addition time: 10 minutes, and the cooling water temperature was 22℃and the flow rate was 11L/min.

Thereafter, the mixture was sieved with a sieve having 200 μm openings to obtain toner 1. Table 4 shows the physical properties of the toner 1 thus obtained.

< Production examples of toners 2 to 26 >

Toners 2 to 26 were obtained in the same manner as in the production example of toner 1 except that the kinds and addition amounts of the silica particles and hydrotalcite particles used were changed to those described in table 4. Table 4 shows the physical properties of the obtained toners 2 to 26. For the toners 18 and 19, the rotation speed of 66.6s ^-1 and the external addition time of 10 minutes of the external addition condition were changed to the rotation speed of 60s ^-1 and the external addition time of 8 minutes. Table 4 shows the physical properties.

TABLE 4

Example 1 ]

The following items were evaluated for toner 1.

< Evaluation device >

A color laser beam printer (HP LaserJet Enterprise Color M652 n) manufactured by Hewlett-Packard was used as an image forming apparatus, and the apparatus was modified to obtain a process speed of 300 mm/sec. The HP 656X original LaserJet toner cartridge (cyan) was used as the cartridge. The product toner was taken out from the inside of the cartridge, the cartridge was cleaned by blowing, and 300g of toner 1 was filled therein. The toner was evaluated by performing the following endurance test by using the cartridge.

< Fusion to developing blade >

The endurance test was performed by outputting 30000 images with a print percentage of 1.0% every 2 sheets for an intermittent time of 2 seconds in a low temperature and low humidity environment (15 ℃/10% RH). For every 1000 sheets, as evaluation images, solid images and halftone images (toner bearing amount 0.25mg/cm ²) were output one by one. Further, after 30000 sheets were printed, the cartridge was taken out from the printer main body, and the melted material on the development blade was visually and microscopically observed. As a microscope, an ultra-deep shape measurement microscope (manufactured by Keyence Corporation) was used.

The evaluation was performed from the evaluation image and the results of visual/microscopic observation based on the following criteria. It is known that in the present endurance test, hydrotalcite particles detached from the toner form aggregates or the like together with spherical silica particles, and the aggregates grow with the endurance use, thereby lowering the evaluation result. C or more was judged to be good.

A: no problems were found on the image and no molten material was observed by microscopy.

B: there was no problem in the image, and a very small amount of molten material was observed by a microscope.

C: in the halftone image, three or more low-density vertical stripes are seen.

D: in the solid image, three or more white longitudinal stripes are seen.

< Initial fogging and after storage >

The evaluation was performed under a high-temperature and high-humidity environment (30 ℃ C./80% RH). First, an image having a white background portion was output at an initial stage of durability, and the fogging concentration (%) was calculated from the difference between the whiteness of the white background portion of the output image measured with "REFLECMETER MODELTC-6DS" (manufactured by Tokyo Denshoku Co., ltd.) and the whiteness of the evaluation paper, and the initial fogging was evaluated. An Amberlite filter was used as the filter.

Thereafter, a durability test was performed by outputting 30000 images with a print percentage of 1.0% every 2 sheets for an intermittent time of 2 seconds. After 30000 images were output, the machine was turned off and the developing device was allowed to stand for 72 hours under the same environment. Thereafter, the machine was turned on again, the fogging concentration (%) was calculated in the same manner as in the initial stage, and the fogging after storage was evaluated. An Amberlite filter was used as the filter. The evaluation criteria were set as follows. C or more was judged to be good.

A: less than 2.0

B:2.0 or more and less than 3.0

C:3.0 or more and less than 4.0

D:4.0 or more

< Examples 2 to 22, comparative examples 1 to 4>

Toners 2 to 26 were evaluated by the above evaluation method. Table 5 shows the evaluation results.

TABLE 5

While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner, comprising:

toner particles; and

Characterized in that the external additive comprises spherical silica particles and hydrotalcite particles,

The sphericity of the spherical silica particles is 0.80 or more, and

The toner satisfies the following formula (1):

{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050 (1)

Wherein Ga: the content of the spherical silica particles with respect to 100 parts by mass of the toner particles;

Gb: the content of the hydrotalcite particles with respect to 100 parts by mass of the toner particles;

Ka%: fixation ratio of the spherical silica particles on the surface of the toner particles;

2. The toner according to claim 1, wherein the toner satisfies the following formula (1'):

6.00≥{Ga×(1-Ka％)}/{Gb×(1-Kb％)}≥0.050(1')。

3. The toner according to claim 1 or 2, wherein an fixation rate ka% of the spherical silica particles on the surface of the toner particles is 60% to 95%.

4. The toner according to claim 1 or 2, wherein an fixation rate kb% of the hydrotalcite particles on the surface of the toner particles is 15% to 70%.

5. The toner according to claim 1 or 2, wherein the hydrotalcite particles have a number average particle diameter Db of 0.10 μm to 1.00 μm.

6. The toner according to claim 1 or 2, wherein the content of the spherical silica particles is 0.10 parts by mass to 5.00 parts by mass with respect to 100 parts by mass of the toner particles.

7. The toner according to claim 1 or 2, wherein the content of the hydrotalcite particles is 0.05 parts by mass to 1.00 parts by mass with respect to 100 parts by mass of the toner particles.

8. The toner according to claim 1 or 2, wherein a ratio Db/Da of a number average particle diameter Db of the hydrotalcite particles to a number average particle diameter Da of the spherical silica particles is 7.5 or more.

9. The toner according to claim 1 or 2, wherein the toner particles are emulsion aggregation toner particles.

10. The toner according to claim 1 or 2, wherein the spherical silica particles are sol-gel silica particles.